DE 102 43 727 C1 discloses an annular baler press belt having reinforcing fabric which is embedded between the rubber covering sheets and is wound from a single rubberized fabric web. As a result of the winding, the fabric web forms, depending on the number of winds, two or more fabric layers lying one atop the other peripherally. The rubberized fabric web with a small thickness is wound over the peripheral length of the annular baler press belt which is provided, until the envisaged number of layers of the fabric reinforcement of the baler press belt is reached, with the result that a continuous fabric belt is obtained immediately. The fabric belt can contain two or more fabric layers.
The two ends of the wound fabric web are cut obliquely with respect to the longitudinal direction of the web and are connected with their ends in an adhering fashion without overlapping one another with the fabric winding on, in each case, one outer side of the winding. Covering strips are applied on the cut, adhered ends. The inner covering strip can be applied by hand. The covering strips preferably have the same oblique angle as the cut web ends.
The covering strips which are attached, on one hand, to the web ends and, on the other hand, to the fabric bonding, are composed of fabric in the form of webbing, for example polyamide fabric in the form of webbing. The open webbing structure of the covering fabric permits the connecting rubber layer of the fabric web to be connected to the outer rubber covering sheets which are applied thereon.
After the lower and the upper rubber covering sheets have been subsequently applied to the continuous fabric winding, this being the fabric core, the continuous belt blank which is produced or assembled is vulcanized. In this context, the rubber covering sheets are connected to the wound fabric core, which is often also referred to by the term carcass. This produces a continuously wound baler press belt, which has proven advantageous in use.
However, the annular baler press belt has a connecting region which is defined by the web ends and which has the effect of reducing the durability owing to the bending cycles which occur during the operation of such annular baler press belts. The carcass is deflected out of the horizontal load plane in the connecting region and is therefore subjected to additional bending loads and additional stretching in the region of the ends of the fabric belt.
In the region of the ends of the fabric belt, a notch occurs in the connecting region. Under dynamic loading, this notch gives rise to peak stresses which the bonding rubber has to withstand. As a result, the requirements which are made of the bonding rubber in terms of material are determined mainly by the configuration of the connection, and considerable potential savings could be achieved in the field of material quality and heating times and run-through times given a configuration of the connection which is subject to less loading.
Given a relatively low winding number of two or three windings or layers, considerable increases in thickness occur in the connecting region with respect to the actual core thickness. This also leads to an increase in the notch sensitivity. The dynamic endurance strength of the connection is not sufficient for many applications.
DE 698 30 206 T2 (EP 1 175 358 B1 and WO 00/35785) discloses a transport belt having a reinforcing core (carcass) which is composed of three fabric layers. Bonding rubber layers are arranged between three fabric layers which lie one atop the other. The two outer fabric layers are covered by outer rubber covering sheets. A belt material is produced with which the continuous connections have to be made, in order to produce a continuous transport belt, after the vulcanized belt material has been cut to length in a special working step and using a particular method. In this context, the web ends are mainly joined together with a hook connection.